A service switching point requires an embedded call model before it can participate in advanced intelligent network services. Large network operators may be required to upgrade their switches with standards based advanced intelligent network (AIN) call models. The messages used for queries and corresponding responses between a service switching point and a service control point typically use the TCAP layer of the SS7 stack. However, the software upgrade required for installing the appropriate call model on the existing switches can be prohibitively expensive, time consuming, and in some cases not feasible. Therefore, it is desirable to be able to add call models to existing service switching points in an economical and timely manner.